Classification structure floral characters and differences of Asteraceae Brassicaceae and Poaceae
Angiosperm is a diverse group. They have stems, roots and leaves and can bear flowers. They have seeds enclosed within the ovary. The angiosperm family includes:
Asteraceae
Brassicaceae
Poaceae
Asteraceae
Characteristics of Asteraceae
They have the following characteristic features:
These are herbs, shrubs or trees. Most of them are xerophytes, hydrophytes and semi-aquatic.
Taproots are modified into tubers.
The stem could be erect, hairy, woody or prostrate. It might sometimes contain latex.
The leaves may be radical, petiolate, exstipulate,
Flowers are tubular or ligulate, bisexual or unisexual, usually dithecous, filament free with united anthers.
Androecium is absent.
Gynoecium is either absent or present.
The seed is endospermic.
The fruit produced is cypsela.
Economic Importance of Asteraceae
Food
Family Asteraceae is an important source of food. The leaves and roots of a couple of angiosperms like garden lettuce and Jerusalem artichoke are edible.
Oil
The seeds of angiosperms are a crucial source of oil.
Medicines
Most of the plants that belong to the Asteraceae family have some of the best medicinal values. For eg., Solidago is employed in dropsy, artemisia yields santonin, the juices and roots of a couple of plants are utilized in bowel disorders and have a cooling effect..
Rubber
Taraxacum and Solidago leavenworthii are a crucial source of rubber.
Insecticide
The capitula of Chrysanthemum roseum is dried and its powder is employed as an insecticide.
Brassicaceae
Characteristics of Brassicaceae
Following are the important characteristics of family Brassicaceae:
These are generally herbs, annuals, biennials, or shrubs.
The taproots are swollen due to food storage.
The stem is erect, herbaceous, and rarely woody.
Leaves are alternate, opposite, simple and exstipulate
Economic Importance of Brassicaceae
Food
The plants of this family are cultivated as vegetable crops. For eg., Brassica oleracea var. Botrytis, Brassica oleracea var. Caulorapa.
Oil
The seeds of the plants of these families are used to extract mustard oil that is extensively used in cooking. For eg., Brassica campestris
The cake left behind after the extraction of oil is employed as cattle feed and fertilizer.
Medicines
The leaves and shoots of plants are utilized in asthma, cough and bleeding piles. They also act as an appetizer and stimulant. The seeds are wont to treat bronchitis and fever. The flowers help in paralysis and impotency.
Ornamentals
Few plants like Iberis amara, Hesperis, Alyssum, bear beautiful flowers and are used for ornamental purposes.
Poaceae
Characteristics of Poaceae
Following are the important characteristics of Poaceae family:
It might be herbs or shrubs, annuals or perennials, and sometimes tree-like.
The roots are often fibrous, adventitious, branched or stilt.
The stem could also be underground as in rhizomes, cylindrical with conspicuous nodes and internodes, woody or herbaceous.
The leaves are alternate, simple, exstipulate, and distichous. The leaf base forms a tubular sheath.
The seeds are endospermic and monocotyledonous.
Fruits include caryopsis, nuts or berry.
Economic Importance of Poaceae
Food
The plants of this family are a crucial food source. For eg., cultivated rice , common wheat , cereal oat (oats), corn (Maize).
Grasses like Panicum, Bermuda grass , Cymbopogon, and Poa are used as fodder.
Sugar
Jaggery and sugar are obtained from Saccharum officinarum.
Building Material
Species of Bambusa are used for scaffolding and thatching of huts.
Aromatic Plants
Many sorts of grass like Vetiveria zizanioides yield scented oil from its roots. The roots are also used to weave curtains.
Medicines
Plants such as Phragmites karka, Claviceps purpurea, Cymbopogon schoenanthus have medicinal values.
FAQs on Asteraceae Brassicaceae and Poaceae in Angiosperms
1. What are Asteraceae, Brassicaceae, and Poaceae in plant classification?
Asteraceae, Brassicaceae, and Poaceae are three major families of angiosperms (flowering plants) classified based on shared floral and morphological characteristics.
- Asteraceae – Known as the sunflower or daisy family, characterized by composite flower heads.
- Brassicaceae – Known as the mustard family, recognized by cruciform flowers and siliqua fruits.
- Poaceae – Known as the grass family, identified by spikelet inflorescences and caryopsis fruits.
2. What are the key characteristics of the family Asteraceae?
The family Asteraceae is characterized by a composite inflorescence called a capitulum (flower head) made of many small florets.
- Inflorescence: Capitulum with ray and disc florets
- Calyx modified into pappus
- Ovary: Inferior and bicarpellary
- Fruit: Cypsela
- Example: Sunflower (Helianthus), Daisy
3. What are the main features of the Brassicaceae family?
The family Brassicaceae is distinguished by its cruciform (cross-shaped) flowers with six stamens arranged in a tetradynamous condition.
- Flowers: Four petals arranged in a cross
- Androecium: Tetradynamous (4 long + 2 short stamens)
- Ovary: Superior and bicarpellary
- Fruit: Siliqua or silicula
- Examples: Mustard (Brassica), Cabbage, Radish
4. What are the defining characteristics of the Poaceae family?
The family Poaceae (grass family) is defined by its spikelet inflorescence and fruit type called caryopsis.
- Stem: Hollow with solid nodes
- Leaves: Parallel venation with leaf sheath
- Inflorescence: Spikelets with glumes
- Fruit: Caryopsis (grain)
- Examples: Wheat, Rice, Maize
5. What is a capitulum in Asteraceae?
A capitulum is a compact inflorescence in Asteraceae where many small florets are arranged on a common receptacle to appear as a single flower.
- Outer florets: Ray florets (often sterile or female)
- Inner florets: Disc florets (usually bisexual)
- Surrounded by involucral bracts
6. What does tetradynamous condition mean in Brassicaceae?
The tetradynamous condition refers to the presence of six stamens arranged as four long and two short in Brassicaceae flowers.
- Total stamens: 6
- Arrangement: 4 longer inner stamens
- 2 shorter outer stamens
7. What type of fruit is found in Poaceae and Brassicaceae?
The family Poaceae produces a caryopsis, while Brassicaceae produces a siliqua or silicula.
- Caryopsis: Dry, one-seeded fruit where seed coat is fused with pericarp (e.g., wheat, rice).
- Siliqua: Elongated dry fruit that splits open to release seeds (e.g., mustard).
8. Why is Poaceae considered economically important?
The family Poaceae is economically important because it includes major cereal crops that form the staple food of the world.
- Food crops: Wheat, Rice, Maize, Barley
- Fodder grasses for livestock
- Bamboo for construction
- Sugarcane for sugar production
9. What is the difference between Asteraceae and Brassicaceae flowers?
The main difference is that Asteraceae has composite flower heads (capitulum), while Brassicaceae has simple cruciform flowers with tetradynamous stamens.
- Asteraceae: Many florets grouped into one head; pappus present; inferior ovary.
- Brassicaceae: Four distinct petals in cross shape; tetradynamous stamens; superior ovary.
10. Are Asteraceae, Brassicaceae, and Poaceae monocots or dicots?
Among these families, Poaceae belongs to monocots, while Asteraceae and Brassicaceae belong to dicots.
- Poaceae: Parallel venation, fibrous roots, monocot embryo.
- Asteraceae: Reticulate venation, taproot system, dicot embryo.
- Brassicaceae: Reticulate venation and dicot characteristics.
